Sheetsxsheet i



p 9, 1952 H. HUMFELD ETAL I 2,610,155

FOAM BREAKER FOR SUBMERGED CULTURE FERMENTOR Original Filed Sept. 12, 1947 2 SHEETS--SHEET 2 INVENTORS HQHUMFELD ll E.AESGHL|MANN J.R.HOFFMAN "(WWW ATTORNEY Patented Sept. 9, 1952 FOAM BREAKER FOR SUBMERGED CULTURE FERMENTOR Harry Humfeld, Berkeley, Ernst Aeschlimann, Oakland, and John R. Hoffman, Berkeley, Calif., assignors to the United States of America as represented by the Secretary of Agriculture Original application September 12, 1947, Serial No. 773,722. Divided and this application November 14, 1950,Serlal No. 197,816

.2 Claims. (Cl. 252-361) (Granted under the act of March .3, 1883, as amended April 30, 1928; 370 0. (11757) This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

This application is a division of our copending application, Serial No. 773,722, filed Septemhas been to attempt to use agitation and also to introduce air directly into the reaction mixture.

These developments brought With them serious problems, the foremost among them being foamformation. Both the agitation and the introduction of air caused such large volumes of foam as to render the method impracticable without modification. One remedy involved the addition to the reaction mixture of chemicals having foambreaking characteristics. This method has the disadvantage of introducing undesired materials into the system and introduces an unknown fac tor into an already complicated problem.

We have invented a fermentor by the use of which iermentations can be carried out at extremely rapid rates. oxygen rduirements of the organisms and agitation is employed to bring about intimate contact between the reactants. At the same time the foam formed is broken down, the gas released to the atmosphere, and the liquid returned to the vessel. N0 foam-breaking chemicals are required.

An object of this invention is to provide a fermentor having both novel aeration and foambreaking devices.

Another object of this invention is to provide a fermentor having a novel aeration device.

Another object of this invention is to provide a fermentor having a novel foam-breaking device.

Other objects and advantages will be apparent to those skilled in the art from the description herein.

The accompanying drawing illustrates the device of this invention, in which:

Air is added to satisfy the 2 Figure 1 is a vertical longitudinal section of the fermentor;

Figure 2 is a horizontal section on line 22 of Figure 1;

Figured is a plan view of the foam-breaking disc, illustrating a method of making it;

Figure 4 is an edge view of the disc;

Figure 5 is a pictorial view of the aeration de vice;

Figure 6 is a top view of the aeration devic the top plate being broken away.

InFigure 1 is shown the assembled device. Vessel I is provided with a lid 2, which serves to cover the contents and to support shaft 3. Shaft 3 extends through lid 2 into the vessel I. At its lower end, shaft 3 is provided with an enlarged boss 29, having a longitudinal bore 30. Shaft 3 is held in place by collars 4 and 5. At its upper end, shaft 3 is provided with suitable means for rotation, such as an electric motor (not illustrated).

The aeration device is situated at the lower end of shaft 3. This device includes a casing comprising upper and lower stationary circular plates 23. and 24 fixed in place by pins 26. Upper plate 23 is attached tobars l9 and 20, which in turn are attached to struts I! and IB. Thus the casing is held stationary. Shaft 3 extends through top plate 23 and is attached at its lower end to 29. To the boss 29 are attached tubes 28 at right angles to the shaft and are curved rearwardly. These tubes communicate with bore 30, Attached to 29 and positioned adjacent to two of the tubes are vanes ll. Bottom plate 24 is provided with a port 25 through which extends pipe 2|. The position of this pipe is adjustable to vary the' proximity of its tip to the inlet of bore 3|]. The adjustment device consists of collars 31, 38, hollow screw 22, and threaded hole 39. Collar 31 is positioned above screw 22 and collar 38 below screw 22. Both of these collars are fastened on pipe 2| by the use of. set screws or other suitable means. Hollow screw 22 is free ly rotatable about pipe 2| and the thread on screw 22 engages inthreads in the hole 39 inthe lid through which the screw and pipe protrude. Upon rotation of screw 22 the entire pipe will be raised or lowered. Thus the proximity of the pipe tip and the bore 30 can be adjusted for the desired amount of air. There is one position of the pipe tip that will give maximum flow of air wh ch can easily be determined with a; flow meter. Raising or lowering the tipfrom this maximum position gives decreasing amount of air flow; Pipe 2| extends from the vicinity of the end of shaft hthmughthe yessel I, lid 2,.and is Open to the atmospher I I Shaft 3 is caused to rotate counterclockw1se at high speed. Rotation of vanes '21 attached to,

the shaft causes flow of liquid up through port 25, bore 30, tubes 28 and radially out'o'fithei. cas '5 .pipe 2| into the liquid stream-where it-pa-sses through bore 3!], tubes 28 andout of the casing. The amount of air enteringf,the;system "can'be regulated by raising or lowering the tip of pipe' 21 as previously described.

Port 25 may be made adjustable in diameter. This can be accomplished bypuse of rotatable ,,.in the vicinity of the interior set of vanes.

gardless of the paths of flow of the materials, i-i-t;has;been observed that in the device as illusfIhus the ,.rising body of foam, has a, dome-like istructure. Iand itappears; thatithe foa'm. actually contacts the disc 9 only" toward the center and itratedpthe foam is broken. In operation the body offoamrises until it just touches the bot- "..tom ofdisc 9. It, goes no further as a body, all'l).

though-the,production of foam progresses con- ;tinuous1y.;-,'Thedevice effectively separates the foam into its components, gas'and liquid, and

ythusit has "been established as an operative device; v regardless of he theory of operation. It has been observed'that cone 1 is not essential,

. although it may be necessary if the volume of laminae 25, such as is employed in makin 'iris diaphragms in photographic cameras. This adjustable feature is advantageous as when the liquid in the fermentor is thoroughly aerated, its apparent specific gravity drops. To maintain the proper flow of air through pipe 2! under such conditions, the volume of material passing through port 25 must be increased and this can easily be accomplished by enlargement of the diameter of the port as described above.

- Mixing and agitating cones l3 and l5 are secured to the shaft 3 by webs I4 and i5, respec'- tively. Rotation of'these cones in the liquid causes violent agitation by reason of the flow of liquid past. the cones due to centrifugal action.

The-foam breaker comprises cones ii and l and disc -9, located above the normal liquid level in vessel I. Gone I is stationary and is supported by struts ll, 18. Gone 6 is secured to shaft 3 via web 8. A passage is provided for flow of fluids between the cones. Beneath the cones a disc 9 is attached to shaft 3 through collar iii. This disc is provided with an inner set of vanes 40, 41 In this inner set, vanes are turned up, while vanes 4| are turned down. The disc 9 is also provided withan outer set of vanes H, l2. In this set, vanes H are turned up and vanes ii are turned down. 'Thus it is evident that the inner set-of vanes is positioned in opposite relation to the outer set of vanes. The result of this is that when the disc 9 is rotated counterclockwise, vanes 40 and 4| tend to force material up toward cone 6 while vanes ll and i2 tend to force ma terial downtoward the body of liquid in the vessel. I

A convenient method of forming the vanes is by drilling holes 32, 53 in disc 9 then making saw cuts along lines 34, 35, and 36. Flap 4B is then bent upwardly about 30 and flap ii is bent downwardly about 30. The other vanes are made in similar fashion.

.In operation, shaft 3 is rotated counterclockwise whereby the interior set of vanes M 41 tend to force material upwardly while exterior vanes ll; l2 tend to force material downwardly. Foam rising from the react-ion mixture contacts the inner series of vanes 45, 4| whereby the foam gthrown upwardlythrough the passage between adjacent vanes onto the inner surface of cone 6. Theirotation of cone 6 forces material down again -O I1t0jdiSC;9beyOIld the inner'series of vanes. Contact with the rapidly spinning disc forces material-toward the walls of the vessel. Some of the material is thrown downward by the outer series of ,nes; ll, I2. Thefiow of liquid and gases Pmducedby rotation of disc 9 0911565 a downdraft aboutthe inner circumference of the vessel whereby-,ioam, is pushed down at this point.

foam suddenly increases and rises through cone 6. In such, case' the foam will be directed back to the outer surface of cone 6 by disc I.

The fermentor of this invention may be provided with conveniences to aid in control of the reaction. For instance, it is usually advisable toadd -a well for a thermometer, a well for an electrode to measure the pH of the reaction mixture and provide one or more sampling tubes. Such devices are easily mounted on lid 2 and pass through holes in cone 1 beyond the periphery of disc 9. A gas outlet is provided at 45.

The apparatus of this invention can be used for growing all types of cultures under submerged conditions. For instance, it may be used for the production of yeasts such as bakers yeast, torula yeast, etc; It 'may be used for the production of .antibiotics'such as subtilin, penicillin, strepto'mycin, andfother antibiotics produced by microorganisms. ;Further, the device may be used for the preparation of various chemical compounds such as citric acid, gluconic acid, acetic acid, and other compounds produced .by micro-biosis. In all such cases the particular micro-organism is grown on the usual media and the use of the device of this invention gives more rapid and economical" production.

Having thus described our invention, we claim:

1. A foam breaker comprising a hollow upright shell providing an inner surface tapering upwardly,.said shell being open at both ends, and a plate mounted below and spaced from, across and beyond the periphery of the lower end of theshell, said plate having inner perforations spaced around its center in the area subtended by the lower end of the shell, upperand lower vanes carried by the plate, each extending circumferentially at least part way across a perforation, the upper vanes being deflected upwardly, the lower vanes being deflected downwardly, the plate carrying outer upper-and lower vanes in the plate area extending outside of the periphery of the lowerend of the shell, the outer upper vanes being deflected upwardly and circumferentially in. opposite direction to the up erinner vanes, the outer lower vanes being deflected downwardly and circumferentially in opposite direction to the inner lowervanes, means 'for mounting and rotating the shell and the plate about an upright axis.

2. A foam breaker comprisinga hollow upright cone having lower-and-upper openends, and a plate mountedand-spacedbelow and across the lower open end of the cone, said plate-having inner perforations spaced about thecenter of the plate,-and outer vanes spaced about the center of, the plate beyond the open lower end'offlth e cone, and inner vanesattached to theplate extending at least part way across the inner perforations, means for mounting and rotating the cone and the plate about an upright axis, the inner vanes extending in the direction required to propel the foam upwardly through the inner perforations and against the inner surface of the 5 REFERENCES CITED The following references are of record in the file of this patent:

Number 6 UNITED STATES PATENTS Name Date v Guest July 26, 1932 Bradford May 2, 1933 J antzen et a1 July 124, 1934 Kimmel July 18, 1944 Gates Jan. 2, 1945 Edwards June 4, 1946 Naucler Aug. 110, 1948 Humfeld et a1 Feb. 20, 1951 

1. A FOAM BREAKER COMPRISING A HOLLOW UPRIGHT SHELL PROVIDING AN INNER SURFACE TAPERING UPWARDLY, SAID SHELL BEING OPEN AT BOTH ENDS, AND A PLATE MOUNTED BELOW AND SPACED FROM, ACROSS AND BEYOND THE PERIPHERY OF THE LOWER END OF THE SHELL, SAID PLATE HAVING INNER PERFORATIONS SPACED AROUND ITS CENTER IN THE AREA SUBTENDED BY THE LOWER END OF THE SHELL, UPPER AND LOWER VANES CARRIED BY THE PLATE, EACH EXTENDING CIRCUMFERENTIALLY AT LEAST PART WAY ACROSS A PERFORATION, THE UPPER VANES BEING DEFLECTED UPWARDLY, THE LOWER VANES BEING DEFLECTED DOWNWARDLY, THE PLATE CARRYING OUTER UPPER AND LOWER VANES IN THE PLATE AREA EXTENDING OUTSIDE OF THE PERIPHERY OF THE LOWER END OF THE SHELL, THE OUTER UPPER VANES BEING DEFLECTED UPWARDLY AND CIRCUMFERENTIALLY IN OPPOSITE DIRECTION TO THE UPPER INNER VANES, THE OUTER LOWER VANES BEING DEFLECTED DOWNWARDLY AND CIRCUMFERENTIALLY IN OPPOSITE DIRECTION TO THE INNER LOWER VANES, MEANS FOR MOUNTING AND ROTATING THE SHELL AND PLATE ABOUT AN UPRIGHT AXIS. 